Methods and apparatus are known for inducing sleep, treating psychosomatic disorders, and for aiding in the induction of hypnosis in a patient, the foregoing being achieved by passing a stimulation of electrical current pulses through the brain of the patient by electrodes attached, for example, to the back of the head and to the forehead. Such apparatus is described, for example, in U.S. Pat. No. 3,762,396. In the apparatus described in the patent, the electric current impulses of the stimulus have a frequency of 8-10 Hz. The apparatus described in the patent also passes a second stimulus of electric pulses to the brain of the patient having a frequency which is four times the frequency of the pulses of the first stimulus, the latter stimulus being introduced through the optic nerves of the patient by the electrodes attached to the temple and forehead. A third auditory stimulus is provided in the system described in the patent by way of sound attenuating chambers. The auditory stimulus is used acoustically to isolate the patient from a noise environment. The three stimuli are preferably synchronized with one another.
U.S. Pat. No. 3,908,634 describes a method and apparatus for inducing a vocalized analgesic condition in the patient by simulating the presence of a hypnotherapist. This is achieved by reproducing a recording of the speech that the hypnotherapist would normally make to the patient.
The apparatus of the present invention falls in the same general class as the apparatus described in the above-mentioned patents; and an objective of the apparatus of the invention, likewise, is to produce different states of consciousness in a patient by repetitive stimuli, with the patient being insulated from external influence. In the practice of the invention, the patient to all intents and purposes is placed in a closed chamber in which the apparatus is set to an operational mode which creates a sensory input; and impulses in the delta, theta, alpha and beta ranges are introduced to the optic cortex, each producing its specific state of consciousness in the patient.
The various ranges referred to above relate to the different rhythms in the brain's electrical activity. For example, the alpha rhythms have a pulse frequency in the 8-13 Hz range; the beta rhythms have a pulse frequency in the 13-30 Hz range; the theta rhythms have a pulse frequency in the 4-7 Hz range; and the delta rhythms are slow waves with pulse frequencies in the 0.5-3 Hz range. The alpha rhythms are customarily found in the normal human adult when he is relaxed and has his eyes closed; the beta rhythms are normally encountered when a person is aroused and anxious; the theta rhythms are often found in adolescents with behavior disorders; and the delta rhythms appear in the normal person when he is asleep.
Each impulse introduced to the patient by the apparatus of the invention is super-imposed on the brainwave activity, finally dominating it and thereby altering the patient's state of awareness. The result is light or deep sleep, somnolence, hypnosis, heightened awareness, or even agitation, depending upon the frequency of the pulses introduced to the patient.
The electrical stimulation is in the form of a modulated square wave accompanied by two sources of audio stimulation, one of which is a sinusoidal tone, modulated by and synchronized with the optical electrical stimulation. The other audio sound helps to overwhelm the circuits, minimizing internal and external inputs. The subject is restricted to the selective sensory impulses he is receiving, and he shuts out most of his internal and external environment, the result being that the impulses received alter the patterns of brain activity essentially bringing the brain into synchronism with the instrument.
Specifically, the present invention provides an improved instrument constructed for electrophysiological stimulation of a human being. The instrument is capable of inducing into the patient the effects produced by brainwave activity in the delta, theta, alpha and beta ranges. The apparatus uses a modulated square wave which creates the electrophysiological stimulation, and which is accompanied by two sources of audio stimulation, one being synchronized with the electrophysiological stimulation. The electrical stimulation is applied to the patient by means of electrodes attached to the forehead.
The audio stimulation is introduced to the patient by means of headphones. One of the audio stimuli is a sinusoidal tone modulated by and in synchronism with the electrophysiological stimulation. The other audio stimulus is derived from a cassette tape player, which plays pre-recorded tapes of special sound effects or hypnotic suggestions recorded for a specific patient.
The result of the foregoing three stimulating forces acting together enables the instrument to alter the mood or mental state of the patient so as to produce a variety of altered mental states. The instrument of the invention can be used, for example, for inducing sleep, inducing an hypnotic state, producing tranquility and relaxation, producing heightened awareness, increasing the ability of a person to concentrate, and for inducing other mental states. The instrument can also be used for treating psychosomatic disorders.
The instrument to be described is battery operated from a self-contained rechargeable 12-volt battery. Battery operation is used for electrical safety, since it completely eliminates the possibility of a patient being electrocuted, as could occur with alternating current line operated equipment.